Case 311 charging system

[bicklebok]

Hello everyone,

I have a Case 311 I have owned for about 5 years now. It was converted to 12V before I bought it but the charging system has never worked. I have finally decided to see if I can get it working over the winter.

Here's what I know:
It was converted to 12V.
It has a Motorcraft charging system-alternator, harness, and voltage regulator (VR). The VR has the terminal connections I A S F.

I purchased a new alternator and VR. Some of the old wired were broken or disconnected and I cant determine where they are supposed to connect.

Questions:

I have looked up old Ford wiring schematics and have seen several diagrams that are different, so I dont know which one to use. I do know the F connector goes to the field connection on the alternator and the A connection goes to the alternator output connector. What about the I connector?

Also, my ammeter connectors on the instrument cluster or shot. Can I just connect the + and - of the ammeter together and bypass the ammeter?

Thank you!

 

[RJKeith]

First, do you have an alternator or a generator. If you have an alternator, I don't think you normally use a voltage regulator. If you do have an alternator, it may be
easiest to take it to an auto parts store and swap it for a new alternator. The new one should have a wiring diagram. Its what I did on my 311.

 

[bicklebok]

It's a ford alternator, not a generator. It's an old school Ford style charging system with an external regulator.

I already bought a new alternator just like the Ford Alternator that someone else mounted on it years ago when they changed to 12V.

 

[Jim.ME]

(quoted from post at 14:27:47 12/14/20)
It's a ford alternator, not a generator. It's an old school Ford style charging system with an external regulator.

I already bought a new alternator just like the Ford Alternator that someone else mounted on it years ago when they changed to 12V.

I think this may be what you are looking for (borrowed from internet images)

 

[DKase]

That is the system I put on all my tractors 45 years ago. I would have to look at my notes in the shop, but I think if you jump 12
volts to the field terminal the alt. will charge full power. That will tell you if it is a regulator problem.

 

[Jim.ME]

Yes, hooking the wires from the + and - terminals of the ammeter together will bypass the ammeter. Another option would be to get another ammeter from a parts store and replace your bad one.

 

[Joe (Wa)]

Are you sure the ammeter is faulty? I've repaired quite a few of these cluster gauge boards and haven't found any ammeters that were anything other than out of zero adjustment. They are the toughest instrument in that panel.

This is how you test them, note the clips swap to change polarity. These are mass production meters not meant to be super accurate. Just get the return to zero set when the power is off so you can detect charge or discharge when the current flow is low, the higher current sweep range will fall fairly close.

Joe

 

[bicklebok]

Thank you for the help gentleman! I will wire it like the diagram Jim posted. I have downloaded several diagrams, but most of them are different in the way they show the regulator connections go. I dont know which one is right.

Joe, one of the threaded posts on the back of the ammeter is rusted and broke almost completely off. I imagine someone with a little welding skills could probably tack it back to the gauge, but I dont have the skills to do that. I thought about buying an aftermarket gauge.

Thank you again. It may be a week or so before I get back to working on it, but I will post an update when I do.

 

[Joe (Wa)]

The meter terminals are brass, no rust there except the surrounding ferrous gauge board metal. The meter terminals are insulated from the holes they pass through on the back of the gauge board. The gauge board is grounded as part of the tractor electrical circuit. An ammeter terminal insulation breakdown will cause a short in the factory 311 generator output circuit.

I don’t know how the circuits were wired for that Ford alternator conversion. There may have been no protection, fuse or otherwise, in the output circuit to prevent a short from damaging the alternator. The only way a short like that will open is if the ammeter terminal burns away from contact with the gauge board or the alternator ceases output. In additional the wiring can become hot enough to cause insulation breakdown and may short out to the tractor frame when a new alternator is powered up. Low voltage, high amp shorts are very hot and continue until something burns open.

The pics are my 1st replacement ~30 years ago of the mechanical temp gauge with an electrical equivalent. Messy looking but it worked. The circled terminals are the ammeter. Probably can’t make it out but I use faucet seat washers for terminal insulators as the washer is perfect fit in the pod terminal holes to hold the ammeter firmly in place.

While we are on the subject, I failed to point out in the meter check response that there is a battery wired series in one of the leads to the ammeter terminal for circuit resistance and provide current load on the charger.

Joe

 

[bicklebok]

Joe, thank you so much for the information! You always come through when I have a question!

Looking at the ammeter posts, they look like they make contact with the back of the cluster to my old eyes, but I know that can be the case. Im going to use your trick and add a plumbing washer to be safe.

Im still going to delete the ammeter because one of the posts is just flopping around, and the part of the cluster the posts passes through is rusted out.